本片描述了香港反黑组的组员惩治罪恶的英勇事迹以及他们个人感情经历的点点滴滴。人称“筋肉人”的反黑组探员阿喜（吴毅将 饰）立功无数、屡破奇案，但却因脾气倔犟，向来专横而和同事们诸多不顺。刚刚加入的康仔（陈浩民 饰）更是对阿喜诸多怨言，甚至想申请调组。后来一起办案多了，反黑组内部终于彼此了解，一团和气。反黑组内也有不少情事，一次上司阿凡（黎耀祥 饰）结识了卖鱼女阿娇，两人成了欢喜冤家；而阿弟（邵美琪 饰）更是一直暗恋阿喜，他们在工作上、感情上正经历着一次又一次的考验。
As Leo's replacement Thomas Chamberlain arrives Nikki investigates the murders of Rachel Freedman, shot in the head, and her little autistic son Nathan, who was poisoned. Nikki rejects policewoman Anne Burchett's theory that Rachel killed them both but is perturbed when an impostor, claiming to be Rachel's sister, visits the morgue. At the same time the disfigured corpse of Eva Liron is discovered, killed with the same poison as Nathan. She had been the nanny to French hot shot footballer Isaac Dreyfus and was planning to blackmail him over a sex tape of them both. Jewish Isaac is a controversial figure due to his anti-Muslim sentiments but he denies ant part in the murders. Then another victim, Isaac's agent Mousa, is discovered dead.
在比萨的一所中学里，从来没有人挑战过那些很酷的孩子们——直到新来的女孩特里带着大胆的想法来到这里，竞争开始了。
